Reheater for elastic-fluid turbines.



No. 794,868. PATENTED JULY 18, 1905.

\ 0. JUNGGREN.

REHEATER FOR ELASTIC FLUID TURBINBS.

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lnv SCaY q gg b5 UNITED STATES Patented July 18, 1905.

PATENT OFFICE.

OSCAR J UNGGREN, OF SCHENECTADY, NEW YORK, ASSIGNOR TO GEN- ERAL ELECTRIC COMPANY, A CORPORATION OF NEWV YORK.

REHEATER FOR ELASTIC-FLUID TURBINES.

SPECIFICATION forming part of Letters Patent No. 794,863, dated July 18, 1905.

Application fi e February 6, 1904;. Serial No. 192,287.

T at whom it may concern.-

Be it known that I, OSCAR J UNGGREN, a citizen of the United States, residing at Schenectady, in the county of Schenectady and State of New York, have invented certain new and useful Improvements in Reheaters for Elastic-Fluid Turbines, of which the following is a specification.

The present invention has for its object to improve the efficiency of elastic-fluid turbines by preventing or largely decreasing the losses due to condensation and radiation as the motive fluid passes through them.

In carrying out my invention the turbine is divided into two or more stages by any suitable means, each stage containing a sufl icient number of buckets to efliciently abstract the energy from the fluid column or columns delivered by the nozzle or nozzles or other discharging devices, which may be expanding or not. Situated in front of and directly in line with the wheel-buckets, which discharge steam or other motive fluid after it passes discharging device.

through them and the nozzle, is a reheating device of suitable construction. The heater may be composed of a coil of pipe and is preferably, although not necessarily, connected to which corresponds approximately to that of the column discharged from the bucket-spaces. In other words, the active area of the wheel in the first stage of a jet-machine being relatively small, the heater may only cover substantially the same area as the nozzle or other Where two or more nozzles are employed, it is best to provide a heater opposite each nozzle. In some special instances, however, I may extend the heater entirely or substantially around the first stage.

To obtain the' best effects, the heater or heaters should be so positioned that they are directly in line with the steam or column of motive fluid issuing from the bucket-wheel, as distinguished from placing them either inside or outside of the column, measured on a radial line. A brief consideration will show the advantage of this arrangement. When the heater is placed at one side of the column, it actsprincipally on a relatively small body of inert vapor; but where it is directly in line with the discharge-orifices of the wheel its heating effect is felt on the entire column.

In order to efficiently heat the discharged column of fluid, the heater should be provided with numerous small passages and intervening hot walls, so as to cause a subdivision of the main column into a number of small streams, which being exposed to the hot walls of the heater pick up heat therefrom rapidly and in an efficient manner.

There is a certain amount of residual velocity in the fluid discharged from the bucket-wheel, and I make use of this to overcome the opposition to flow offered by the heater.

In the subsequent stages the nozzles cover a greater area than in the first stage and the area increases to the exhaust in successive steps. In the last stage they usually extend entirely around the wheel. The nozzles may be in alinement or in advance or behind an axial plane passing through the first nozzle. In a general way I make the heaters conform to the nozzle arrangement in so far as it is possible without undue complication. The last wheel exhausts directly into the condenser or conduit leading thereto, and of course no heater is provided at that point.

The energy for the heaters may be supplied in a number of different ways, as by heated vapor or liquids. It will be found satisfactory to supply them with live steam received from the boiler direct or from the steam-chest of the first stage. The various heaters may be connected in series or multiple, as best suits the conditions of operation.

In addition to reheating the column of fluid exhausting from the wheels to reduce condensation I heat the nozzles by means of steamreceiving chambers, which Wholly or partially surround them. The nozzles may be made in any suitable way; but I consider it best to cast them with the chamber or chambers formed in the same piece. These chambers should be charge-orifices should be as thin as" possible consistent with the requisite strength. It is advantageous to form the nozzles and their heating-chambers in the diaphragms which separate one wheel-compartment or stage from the next or in the supports for the diaphragms, since by so doing the construction is simplified and the heat due to radiation serves to heat the exhaust in the wheel-casing. The chambers may be connected to the heaters in the wheel-compartments or they may be connected together in a separate circuit. A simple and satisfactory arrangement is to connect the heater in the first stage to the nozzle-heating chamber of the second stage, and so on.

The word reheating as used in the specification and claims should be interpreted as covv ering the idea of increasing the temperature of the motive fluid above normal, whether said increase be sufiiclent to superheat or not.

In the accompanying drawing, which illustrates one embodiment of my invention, is shown a partial vertical section of an elasticfluid turbine of the four-stage jet type, having two rows of bucket-wheels per stage.

1 represents the casing of the machine, which is made up in suitable sections. The upper end of the casing is provided with a cover or wall 2 and is divided into wheel-compartments by the walls or diaphragms 3. The

high-pressure diaphragm is made somewhat smaller than the low-pressure diaphragm, so as to decrease the total pressure to vwhich it is subjected and is supported by a shoulder 4, formed on the inner surface of the casing.

The remaining diaphragms are supported on small shoulders 5.

6 represents the bucket-wheel, which is prov vided with rows of buckets 7. Between the in practically a solid column.

buckets on the wheel are located intermediate buckets 8, which in the first stages extend only partly around the wheel, but in the stage of lowest pressure may extend all the way around. These buckets are supported in any suitable manner from the casing. Steam or other elastic fluid is discharged against the wheels by' means of the expanding-nozzles 9.

The nozzles are preferably composed of a plurality of closely-associated nozzle-sections, which are so arranged that they discharge the steam One or more nozzles may be provided for the first stage, depending on the power delivered by the machine. The area of the discharge-orifices of the nozzles increases from the high-pressure to the exhaust, as is readily seen from an inspection of the drawing. The admission of fluid to each of the high-pressure-nozzle secceeding nozzles and buckets, so as to act on the fluid column as it emerges therefrom. The succeeding heaters after'the first are arranged to cover a greater angular space as they approach the exhaust. For example, the heater 13 extends farther around the wheel than the first-stage heater 12, as is shown by the dotted lines, whereas the third-stageheater 14 extends entirely around the wheel. The second-stage nozzle 15 differs from the other nozzles in that it is formed in the casing. Located on opposite sides of the nozzle are connecting-chambers 16, which are adapted to receive heated fluid for increasing the temperature of the motive fluid passing through it. The nozzles 17 of the lower-pressure stages are formed in the diaphragms, wherein each nozzle is partially or wholly surrounded by connecting-chambers 18, which heat the motive fluid as it passes through them. In addition to heating the relatively thin walls of the nozzle and its bowl the chambers 16 and 18 tend to increase the temperature of the whole wheel-chamber, and therefore to decrease condensation. As shown, the reheating-coils and the nozzle-heaters are connected in series by the pipes 19 and 20, the pipes 19 connecting each reheater with the adjacent chamber surrounding the nozzle and the latter connecting the chamber around one nozzle with the reheating device in the ad ja- "cent stage of lower pressure.

The means employed to supply heat to the reheaters and Vaporizers can be modified without departing from the spirit of my invention.

In accordance with the provisions of the patent statutes I have described the principle of operation of my invention, together with the apparatus which I now consider to represent the best embodiment thereof; but I desire to have it understood that the apparatus shown is only illustrative and that the invention can be carried out by other means;

What I claim as new, and desire to secure by Letters Patent of the United States, is-

1. An elastic-fluid turbine comprising a bucket-wheel and a device for discharging motive fluid against the bucket-wheel, in combination with a means in which a heating medium of a temperature higher than that of the motive fluid is adapted to circulate for imparting heat to the motive fluid as it passes through the said device.

2. An elastic-fluid turbine comprising a casing, diaphragms dividing the same into a plurality of stages, bucket-wheels for the stages arranged one after the other, the high-pressure wheel being located at oneend and the low-pressure wheel at the other, nozzles for discharging motive fluid against the wheels, a reheater for each stage situated between the wheel and diaphragm and directly in front of the column of fluid discharged by a nozzle and wheel, and a source of heat energy for the re heaters. I

3. An elastic-fluid turbine comprising a plurality of stages, a bucket-wheel for each stage, nozzles for discharging motive fluid against the wheels, the discharge area of which increase from the turbine-inlet to the exhaust,

and reheaters for the stages which increase their effective area toward the exhaust.

4:. An elastic-fluid turbine comprising a plurality of stages, a bucket-wheel for each stage, nozzles for discharging motive fluid against the wheels, a reheater for a high-pressure stage, which extends partially around the wheel, and a reheater in a subsequent stage of lower pressure, which extends completely around the wheel.

5. An elastic fluid turbine comprising wheel-compartments and nozzles or devices for discharging motive fluid against the wheels, means for heating the nozzles, and reheaters for increasing the temperature of the fluid column discharged by certain of the nozzles and wheels.

6. An elastic fluid turbine comprising wheel-compartments and nozzles or devices for discharging motive fluid against the wheels, in combination with fluid-containing chambers for heating the nozzles, reheaters between stages, and connections for supplying a heated fluid to the chambers and the reheaters.

7. An elastic-fluid turbine comprising a plurality of stages, each stage containing a nozzle and a bucket-wheel, in combination with heaters for the nozzles, heaters for reheating the column of fluid discharged from the buckets, and connections for connecting the nozzle heaters and reheaters.

8. An elastic-fluid turbine comprising a plurality of stages, each stage containing a nozzle and a bucket-wheel, in combination with heating-chambers for the nozzles, heaters for reheating the column of fluid discharged by the buckets, and means for connecting the chambers and heaters with the same source of energy.

9. In a turbine, the combination of a casing, a bucket-wheel, a wall, a nozzle or discharging device carried by the wall, and a heater for the nozzle or device which is movable with the wall.

10. In a turbine, the combination of a casing, a wall forming a part of a wheel-compartment, a nozzle formed in the wall, and aheating-charnber for the nozzle also formed in the wall.

11. In a turbine, the combination of a casing, a plurality of diaphragms for dividing the casing into compartments, expanding-nozzles carried by the diaphragrns, and heaters for increasing the temperature of the nozzlewalls.

12. In a turbine, the combination of acasing having an overhanging projection, a sectionalized nozzle formed in the projection, and chambers also formed in the projection through which a heating medium is passed to raise the temperature of the fluid passing through the nozzle.

13. An elastic fluid turbine comprising Wheels, compartments therefor, and nozzles or devices in the stationary part of the turbine for'discharging motive fluid against the wheels, and heating-chambers surrounding the nozzles for heating the walls of the latter.

In witness whereof I have hereunto set my hand this 4th day of February, 1904.

OSCAR J UNGGREN. 

